Studing a good way to improve speed with avisynth, I tested some different path…

New CPU: obvious… but take in account the complete cpubenchmark score, not only the single thread - if, for example, your old dual core CPU has a single thread score of 500 and complete score of 1000, and the new quad core has a single thread score of 1000 and complete score of 4000, it will go four time faster, more or less!
Faster HDD (or better SSD): haven’t tried an SSD yet, but I’m pretty sure this will not improve the overall speed.
Avisynth 64bit: could indeed improve speed, but it has quite few compatible plugins…
MT version and other multithread plugins: could work, but sometimes MT crashes, and other plugins didn’t work - probably my fault
Parallel encoding: it works well! Follow me…

I tried this path in the latest days; I didn’t dare to try it with my poor old dual core, dual threaded CPU, but with the new quad core, eight treaded one, I wanted to give it a try… and, oh boys, it works, very well!

How it works?

Well, just take your script, and “cut” it in several pieces - it seems that four pieces works well here, they run the CPU at around 80%, leaving some breath for surfing and other little things; probably it could work with more pieces, but your mileage can vary.

Before

project1.avs
avisource(“your source.avi”)
filter1
filter2
filter3
[/code]

After

project1_part1.avs

avisource(“your source.avi”)
filter1
filter2
filter3
trim(000000,040020)

project1_part2.avs

avisource(“your source.avi”)
filter1
filter2
filter3
trim(040000,080020)

project1_part3.avs

avisource(“your source.avi”)
filter1
filter2
filter3
trim(080000,120020)

project1_part4.avs

avisource(“your source.avi”)
filter1
filter2
filter3
trim(120000,000000)

project1_final.avs

a=avisource(“project1_part1.avi”).trim(000000,039999)
b=avisource(“project1_part2.avi”).trim(000000,039999)
c=avisource(“project1_part3.avi”).trim(000000,039999)
d=avisource(“project1_part4.avi”)

a+b+c+d

Encode them at the same time; speed improvement: from 250% up to 400%, depending on how “heavy” are the filters/plugins…

You know, instead of waiting, let’s say, two days, it’s better to wait “just” 12 hours, don’t you think?

Hope this would be of some help.